Protesters burn a portrait of Vladimir Putin at a memorial march for Boris Nemtsov, in Mariupol, Ukraine.
Photograph: Sergey Vaganov/EPA

With the murder of Boris Nemtsov, Russia’s beleaguered liberal opposition has lost one of its last audible voices. There was a brief period, after parliamentary elections in late 2011, when street dissent seemed on the rise, and large rallies gripped Moscow.

The optimism dissipated however, after Putin won another resounding victory in the March 2012 presidential elections. The day before his inauguration, a huge protest turned violent. In a sign that any radicalisation would not be tolerated, a number of protesters were put on trial, often for extremely minor offences, and threatened with years in jail.

Since then, the opposition’s mood has been on the wane, with urban liberals either making plans to leave Russia or simply getting on with life, feeling they have more to lose than to gain by protesting.

Russia’s parliament is dominated by the pro-Putin United Russia party but also has three parties nominally in opposition: Just Russia, the Liberal Democrats and the Communists. While these parties are given airtime on television and – especially in the case of the Communists – have a genuine electorate, they are best described as “systemic opposition”, managed by the Kremlin.

Among the “non-systemic” opposition, there are few politicians who have much of a national profile, with the restrictions of state television meaning it is hard to gain a real platform. Harassment, threats and fatigue have led many into either jail or exile. Now that Nemtsov has been silenced, here are a list of the main opposition figureheads.

Mikhail Khodorkovsky

Once Russia’s richest man, Khodorkovsky was jailed in 2003, on charges widely believed to be politically motivated after he began financing political parties. He spent a decade in prison but was released in December 2013 after Putin granted him amnesty.

He has set up the Open Russia Foundation and is prepared to go “all the way” to change the regime in Russia. However, although Khodorkovsky may have impressed some with his stoical handling of a decade in prison, most Russians have little regard for those who made billions in the 1990s, and it is also unclear how much he can influence politics from outside the country.

Garry Kasparov

The former world chess champion became a fierce critic of Putin and was a frequent fixture at opposition events for many years, often being detained by police. In 2013, he announced at a press conference in Geneva that he had decided not to return to Russia as, after criminal charges were brought against Navalny and other opposition activists, he could be next.

Alexei Navalny

A blogger and lawyer who gained a huge following for his investigations into corruption among Putin’s elite, Navalny came to prominence during the wave of street protests in Moscow at the end of 2011, and was widely seen as the brightest hope for the opposition.

Some are disturbed by his Russian nationalist views while others point out that they could help him gain broader support among Russians who would not normally support the opposition.

Since he came to prominence, Navalny has had to deal with a wave of bureaucratic and legal hassles, including two major court cases. At the end of last year, Navalny was given a suspended sentence in a fraud trial, but his brother was sentenced to 3and-a-half years in prison.

Navalny says authorities have effectively taken his brother hostage in an attempt to stop him working but he has vowed to continue. He was not at Sunday’s march in Moscow, having been jailed for 15 days when handing out leaflets advertising the event – back when it was still an “anti-crisis rally” and not a memorial for Nemtsov.

Igor Strelkov

It has been suggested for a long time that the serious popular threat to Putin comes not from liberals but from nationalists, and these forces have been newly invigorated by the war in east Ukraine. Indeed, one theory is that rogue nationalist groups could be behind the killing of Nemtsov.

Strelkov, a fan of military re-enactments, fought for Russia in Chechnya and more recently helped coordinate the pro-Russian rebel movement in eastern Ukraine. Called back to Moscow after apparently going rogue, he has said he believes Russia will soon be engulfed by war.

“His analysis is simple,” said Alexander Borodai, another Russian leader of the Donbass rebels. “There is a crisis in the country, the government will fall soon, and in the inevitable civil war, Igor Strelkov will head patriotic forces and become the dictator of what is left of Russia.”

The scenario seems unlikely but there is no doubt that serious thought is being given as to whether the promotion of Russian nationalism in the armed conflict in Ukraine might have let a genie out of the bottle.

Sergei Udaltsov

A familiar face at opposition protests for years, 38-year-old Udaltsov is a hardcore radical leftist, who has been detained on numerous occasions at rallies. He was charged as part of the “mass disturbances” case over a May 2012 rally that turned violent, and was sentenced to 4 and-a-half years in prison. From jail, he has said that liberals and leftists must go separate ways now, due to their different positions on the conflict in Ukraine, and while he still opposes Putin, he calls for a new union of far-left forces.